Q&A: Kelp Farming on the Salish Sea
A team of Washington seaweed enthusiasts wants to make sure kelp farmers and policy makers have access to all the best science.
A team from Washington recently published a paper describing the issues around kelp farming on the Salish Sea, a relatively new industry in the region. I tracked down the authors and they agreed to answer a few questions for readers of this newsletter. Many thanks to Emily Buckner, Nicole Naar, Grace Adams, Joth Davis, Sean Matson, and Daniel Tonnes for working with me on this Q&A.
Who are you guys, exactly?
We are a group involved in Washington aquaculture from a variety of perspectives—federal management, Sea Grant extension support, farming, and research.
What are kelp?
Kelp are large brown seaweeds found in coastal temperate and polar waters along shorelines across the world. As photosynthesizing marine organisms, they grow at depths where sunlight can reach the seafloor. They create marine “forests” that provide critical habitat for nearshore fishes, invertebrates, and mammals.
Why are kelp farmed? What can you do with them?
Seaweeds are farmed for a variety of reasons globally, including for food, pharmaceuticals/cosmetics, animal feed, and fertilizer. Many farmers are drawn to kelp because they require no food or fertilizers and improve local water quality by absorbing carbon dioxide and excess nutrients. Others are interested in the potential of farmed kelp to clean up contaminated waterways, since it can also absorb heavy metals and other pollutants. Still others cite benefits to the ecosystem, such as improved water quality, habitat for marine life, and protection of shoreline from waves.
Kelp is also cultivated to support restoration efforts where climate change and other stressors have impacted wild kelp populations in recent years.
Is kelp safe to eat if it has been absorbing heavy metals and pollutants?
This is a great question, and one that folks at Western Washington University have been working to answer. They published a paper on this topic a couple years ago. Their results suggest that the concentration of pollutants and heavy metals in edible seaweeds varies by location. This is one of the many reasons we emphasized the importance of choosing an appropriate site in our paper!
How did you get into kelp farming?
There has been growing interest in kelp farming in Washington state over the last several years, as it has developed as an industry on the east coast, Alaska, and British Columbia. Due to this interest, regulatory agencies have been faced with considering how to permit this new type of farming in our state waters and how to ensure that these activities are conducted in a socially and ecologically responsible manner.
But there is a lack information on the positive or negative impacts of kelp farming in local waters. We saw that there was a critical need to compile the best available science on kelp farming globally to inform regulatory decision-makers and would-be farmers.
Are our native kelp good candidates for kelp farming?
Yes! It is illegal to grow a non-native seaweed species in Washington waters, so only native species are permitted. The most popular species, both locally, and in other parts of the country, is sugar kelp (Saccharina latissima). But many other native species may be good candidates as well, though some cultivation testing may be needed.
Where on the Salish Sea is there the most interest?
Currently, operating and proposed kelp farms are located around Vashon island (central Puget Sound), north Hood Canal, and the northeast San Juan Islands.
Are there potential kelp farming sites in Southwest Washington, either in South Puget Sound or on the outer coast?
We are not aware of any currently proposed kelp farm sites in the South Puget Sound basin or the outer coast. However, there are some kelp restoration sites in South Puget Sound that use conservation aquaculture techniques to grow young kelp.
What obstacles have gotten in the way as people have attempted to get the industry rolling?
One of the largest obstacles to date has been the permitting process. Because this is an emerging industry, regulators are working in real time to develop the process and determine guidelines and restrictions.
As part of that permitting process, local citizens have the opportunity to provide comments and input before permits are issued. Some residents near proposed farms are supportive, while others have voiced concerns about impacts to their viewscape or the potential for marine mammals to become entangled in the floating lines that the kelp are grown on.
What are some potential solutions to these obstacles?
The permitting process should become more streamlined as regulatory and leasing agencies gain familiarity with seaweed farming, and as research on ecological effects is funded, carried out and communicated. Increased education about kelp farming may also help garner more local support and decrease push-back.
Are their any ecological concerns?
Ecological concerns in our region include entanglement risks to marine mammals, shading of seafloor vegetation such as eelgrass, and threats to wild populations of kelp from disease or genetic drift of cultivated kelp.
However, we believe that all of these concerns can likely be mitigated or significantly decreased through best farming practices. These include, among others:
Choosing farm sites outside of areas frequented by high risk marine mammals (gray and humpback whales) and away from eelgrass beds
Using well-designed farming infrastructure to reduce the likelihood of entanglement
Using seed from local kelp populations for cultivation.
What else should we know about kelp farming?
One of the most important considerations for a would-be farmer is to understand tribal treaty rights in Washington state and learn which tribe or tribes have “usual and accustomed” (U&A) fishing areas in the waters where they would like to start a farm. Support from these tribal governments is required to move forward in the permitting process and is best sought through early and collaborative discussions.
Thank you so much—this has been great! Do you have anything else you would like to promote?
You’re welcome! To learn more about kelp farming and conservation in Puget Sound, to keep up to date on local research and regulations, and to meet other farmers, check out the Washington Sea Grant, Washington DNR Aquatics, and the Northwest Straits Commission.
Image credit: Saccharina latissima by Baralloco, CC BY-SA 3.0.
